Slideway grinding machine



Jan. 31, 1961 o. BRETSCHER 2,969,620

SLIDEWAY GRINDING MACHINE Filed Aug. 4, 1958 4 Sheets-Sheet 1 Fig. I

INVENTOR.

W70 ea-Tram Jan. 31, 1961 QBRETSCHER 2,969,620

I SLIDEWAY GRINDING MACHINE Filed Aug. 4, 1958 4 Sheets-Sheet 2 Fig.2

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INVENTOR.

Jan. 31, 1961 o. BRETSCHER.

SLIDEWAY GRINDING MACHINE 4 Sheets-Sheet 3,

Filed Aug. 4, 1958 'II 55 ll v mwgwrok arm B/WK E hm lfflf Jan. 31, 1961 o. BRETSCHER 2,969,620

SLIDEWAY GRINDING MACHINE Filed Aug. 4. 1958 4 Sheets-Sheet 4 2,969,620 Patented Jan. 31, 1961 SLIDEWAY GRINDING MACHINE Otto Bretscher, Dorf, Canton Zurich, Switzerland, assignor to Ludw. von Rollschen Eisenwerke A.G., Gerlafingen, Switzerland Filed Aug. 4, 1958, Ser. No. 752,758

Claims priority, application Austria Aug. 2, 1957 6 Claims. (Ci. 51-72) This invention relates to the class of machine tools, and more particularly to a slideway grinding machine.

An object of this invention resides in the provision of means whereby a grinder may be secured on the crossarm of a machine tool, which grinder can be rotated horizontally and adjusted vertically in the perpendicularly extending guides of a slide.

Swiveling grinders are known in different variants, which are secured on the crossarm of machine tools.

But they all have considerable disadvantages, either in other and a driving motor are carried by the support.

with the axis of rotation of the motor being spaced from that of the grinding disks and extending parallel thereto. The support also is pivoted to a yoke secured on the vertical slide and projecting over the motor and the grinding disks.

Yet another object of the present invention resides in the provision of means facilitating the shaping of the contours of the grinding disks.

An additional object of the invention resides in the provision of means affording control of the peripheral speed of the grinding disks in response to the position of a turning device for shaping the contours of the grinding disks.v

An important feature of the invention resides in the novel use of hydraulic clamping means for maintaining the various parts of the invention in a locked position when the grinder is being used, which clamping means also dampens vibrations resulting from grinding operations or operation of the motor.

Still further objects of the invention reside in the provision of a slideway grinding machine that is relatively simple in construction, easy to operate, flexible in use, strong and durable, and of high precision.

These, together with the various ancillary objects and features of the invention will become apparent as the following description proceeds, reference being had to the accompanying drawings, illustrating an embodiment of the grinding machine by way of example only, and wherein:

Fig. l is a vertical sectional view of the slideway grinding machine with various parts being shown in front elevation;

Fig. 2 is a transverse vertical sectional view of the grinder particularly illustrating the yoke and pivotal mounting of the support;

Fig. 3 is a horizontal sectional view illustrating in particular the cooperation of the cross slide and the vertical slide;

Fig. 4 is an enlarged partial horizontal sectional detail view, similar to Fig. 3, particularly illustrating the construction of the hydraulic clamping means;

Fig. 5 is a detail sectional View illustrating the construction of shaping means for the grinding disks;

Fig. 6 is a sectional detail view showing the construction of turning devices for the grinding disks and the associated motor speed control device;

Fig. 7 is a horizontal sectional detail view of the turning devices; and

Figs. 8 to 13 illustrate various grinding positions of the grinding machine with respect to a workpiece.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, reference numeral 1 designates the crossarm of a machine tool, for example, a slideway grinding machine. The invention includes a cross slide 2 which engages with its slideways 3 of the dovetail guide of the crossarm'l and which can slide on the crossarm 1 in a horizontal direction. At the top of the cross slide 2 are arranged spring guide rollers having an inclination such that the slide 2 is pulledv upward with a slight counterbalance into the dovetail guide 3 and at the same time to the rear to the crossarm 1.

A vertical slide 4 is providedwith slideways 5 for vertical movement with respect to the cross slide 2. On the vertical slide 4 there is pivoted the support 6 which is mounted with a cylindrical lug 7 in a corresponding bore of the vertical slide 4. This support 6 is also supported in a second bearing, since the axle 10 of the support is journalled in the yoke 11. This yoke 11 is rigidly mounted on the upper side of the slide 4 and embraces the motor and the grinding disks so that the support can rotate freely and completely throughout 360.

Above the grinding disks is arranged the motor 12, secured on the support 6, which drives shaft 77 carrying both grinding disks 8, 9 together by means of a belt 13.

Electric current is supplied to this motor by commutating' means including slip rings 17 which are provided between the support 6 and the slide 4.

The axisof rotation of the support is located between the axis of rotation of the grinding disks and the axis of rotation of the motor and extends normal to the latter.

The support 6 can be swiveled about the cylindrical lug and the journal 10 by means of a gear rim 14 which is engaged by a pinion 15. The swiveling of the support can be efiected either by a hand lever 16 or by a motor drive. Since the yoke 11 projects both over the motor and the grinding disks 8, 9 as well as over all parts secured on the support, it is possible to turn the support with the parts secured throughout 360 degrees.

The vertical adjustment of the slide 4 is effected by a spindle 18 which cooperates with a worm gear and a drive shaft and can be put in motion either byv hand or by a motor. The horizontal adjustment of the grinder is effected by means of a motor 19 which acts over a gear on a horizontal spindle.

Two hydraulically operated clamping elements are provided to lock the support 6 on the slide 4 and the slide 4 on the slide 2. The accidental rotation of the support with regard to the slide is prevented by these clamping elements as illustrated in Fig. 4. These clamping elements include a bolt 20, over which is pushed a sleeve 22, which bears with a shoulder on the gear rim 14. By means of the spring 21 the sleeve 22 is pressed against the stop plate 23 so that a rigid immovable connection is established in reset position between the parts. Above the spring 21 is arranged a piston 24 moving in a bore, over which is provided a hollow space 25.- The latter is connected with a feed line 26 for pressure oil.

As soon as oil under presure is fed to this space, the bolt 20 moves against the pressure of the spring 21, thus releasing the sleeve 22 so that the support can be moved freely by means of the gear rim.

A similar clamping device exists between the slideways and the cross slide 2 where the head 62 of a bolt 63 embraces partly the slideway pressing against the guides, and is released again under the action of the liquid under pressure to effect a displacement. The construction could naturally also be reversed in the sense that the clamping is eiiected under the action of the pressure oil and the spring effects the opening.

Due to the clamping elements a further increase of the precision is achieved, since the clamping elements will dampen vibrations and since the position of the parts riding on each other becomes independent of the accidental thickness of the lubricating film.

The slideways 5 glide on elastically mounted rollers 27 to facilitate the adjustment as far as possible. The adjusting elements are relieved by the resulting rolling friction so that even minute displacements can be effected with high precision. The rollers 27 turn about a bolt 28 which rests in a bearing part 29. Between this bearing part 29 and a cover 30 rigidly connected with the slide,

is arranged a spring 31 which urges the roller 27 to abut the slideway. The rollers spring back during the clamping so that the slideway rests directly on the counterguide.

The whole grinder is suspended on a supporting rail 32 forming part of the crossarm 1. To this end a cylinder is formed on the vertical slide by means of a cylindrical bore 33 provided in the yoke 11, in which cylinder slides a piston 34. The bore 33 is closed leak-proof at the top with a cover 35 forming the upper Wall of the cylinder.

The supporting bar 36 secured on the piston 34 is arranged on the roller frame 37 which can move back and forth on the supporting rail 32 by means of rollers 38. In the chamber 39 between the piston 34 and the cover 35 is arranged a liquid, for example, oil, which is put under pressure by any suitable conventional means such as a pump (not represented). is so adjusted that the total force resulting from oil under pressure acting on the piston is somewhat higher than the force resulting from the weight of the grinder, so that the guiding elements are relieved to a great extent. The bore 33 is so arranged with regard to the center of gravity of the grinder that there is not pitching moment on the vertical slideways 5.

In order to provide the grinding disk with a suitable. profile, for example, a positive or negative V-profile for corresponding slideways, the grinder is provided according to Figs. 1 and 5 at least on one of the grinding disks with a rolling device. The latter is so secured on the support 6 that it comes to lie at a point approximately diametrically opposite the grinding surface of the disk. This rolling device has an arm 46 which is pivotally mounted on the pin 47 and which can be turned by means of the spindle 48 and the gear 4% radially to the grinding disk 9.

In the arm 46 is pivotally mounted a profiled roller 44 or a cylindrical roller which is pressed against the rotating disk by actuating the gear 49, so that the profiled roller rolls on the disk. Due to the contact pressure the abrasive grains break out of the grinding disk so that finally the desired profile corresponding to the roller is obtained. Instead of a swivel arm 46 a slide, adjustable rectilinearly and radially to the grinding disk 9, could also be used as a carrier for the profiled roller.

For the cylindrical truing of the grinding disks a truing device for each grinding disk is provided on the bearing block between the latter and the supporting clip for each grinding disk. These have a slide 50, moving parallel to the axis of rotation of the grinding disks, which carries at both ends a slide 51, adjustable in a right angle thereto,

The oil pressure.

with the diamond holders 52. In the diamond holders 52 are arranged diamond tips 53, the holder being adjusted by means of adjusting screws 54 to the radius of the grinding disks. The motion of the slide 50 parallel to the axis of the grinding disk is eiiected by means of a conventional hydraulic system having a piston 55 and a control device (not represented in the drawing) by which the reciprocating motion can be infinitely regulated.

On both slides 50 is arranged a contact slide 56 each, which glides over the fixed resistance 57 when the slide 58 is adjusted, thus varying the resistance and influencing directly or over auxiliary devices the speed of the driving motor for the grinding disks. A by-pass switch may, of course, be provided. The peripheral speed of the grinding disks is thus controlled independent of their diameter. It is thus possible to obtain always the optimum peripheral speed, even for worn grinding disks, without any danger that, when new grinding disks are used, an undesirable peripheral speed remains set out of carelessness, since the insertion of the new disk necessarily results in an adjustment to the corresponding larger diameter. The motor speed is determined by the larger grinding disk.

Figs. 8 to 13 show examples of possible uses of the grinder in the grinding of slideways of a machine tool stand. As it can be seen from Figs. 1 and 12 a plateshaped grinding disk 58, which is connected by suitable means with the drive shaft of the grinding disks 9, can be provided additionally in order to increase its range of application. Naturally the grinder could also be secured on machine tools whose use consists not only in grinding, for example, on upright cutting and planing machines.

In spite of its universal applicability and of its great field of traverse, this grinder is highly rigid and stable, and it permits a considerable increase of the grinding precision, compared to other known grinders.

In Fig. 8, the grinding disk 9 in an initial position grinds the horizontal surface 81 of workpiece 80. When romated throughout approximately 30 degrees, as in- Fig. 9, the grinding disk 9 can grind the slanting slideway 82.

As shown in Fig. 10, the grinding disk 10 can be contoured to facilitate its use in grinding the triangularshaped surface 83.

When rotated in the opposite direction from Fig. 9, as can be seen in Fig. 11, surface 841 of the slide can be easily ground. Surfaces 85 and 86 can be ground with the grinder in the position shown in Figs. 12 and 13 using auxiliary grinding wheel 58 and grinding disk 8, respectively. It is to be understood that this grinding machine is very flexible in use.

Thus it can be seen that there has been disclosed a grinding machine comprising a crossarm 1, 32, a cross slide 2, means 4t}, 33, 36, etc. suspending the cross slide 2 from said crossarm 1, 32 for horizontal movement therealong, a vertical slide 4 mounted on the cross slide 2 for vertical movement relative thereto, a support 6 pivotally mounted on the vertical slide 4, a motor 12 carried by the support 6, a shaft 77 journaled in the support 6 and driven by the motor 12, the shaft '77 having an axis of rotation spaced from the axis of rotation of the motor 12, grinding disks 3, 9 on the shaft 77, and a yoke llll propping support 6 secured to the vertical slide 4, the support 6 being pivoted to the yoke 11.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A grinder comprising a crossarm, a cross slide means suspending said cross slide from said crossarm for horizontal movement relative thereto, a vertical slide mounted on said cross slide for vertical movement relative thereto, hydraulic means for locking said vertical slide relative to said cross slide, a yoke on said vertical slide, a support pivoted to said vertical slide and said yoke, hydraulic means for locking said support to said vertical slide in adjusted position against rotation, a motor carried by said support, and a shaft having grinding disks thereon journalled in said support and being driven by said motor.

2. A grinder comprising a crossarm, a cross slide means suspending said cross slide from said cross arm for horizontal movement relative thereto, a vertical slide mounted on said cross slide for vertical movement relative thereto, hydraulic means for locking said vertical slide relative to said cross slide, a yoke on said vertical slide, a support pivoted to said vertical slide and said yoke, hydraulic means for locking said support to said vertical slide in adjusted position against rotation, a motor carried by said support, a shaft having grinding disks thereon journalled in said support and being driven by said motor, said means suspending said cross slide from said supporting rail including a roller frame engaging said supporting rail, a closed cylinder on said cross slide, a piston depending from said roller frame and extending into said cylinder, and fluid under pressure in said cylinder holding said piston in spaced relation in said cylinder with respect to the upper end of said cylinder.

3. A grinder comprising a crossarm, a cross slide means suspending said cross slide from said crossarm for horizontal movement relative thereto, a vertical slide mounted on said cross slide for vertical movement relative thereto, hydraulic means for locking said vertical slide relative to said cross slide, a yoke on said vertical slide, a support pivoted to said vertical slide and said yoke, hydraulic means for locking said support to said vertical slide in adjusted position against rotation, a motor carried by said support, a shaft having grinding disks thereon journalled in said support and being driven by said motor, said means suspending said cross slide from said supporting rail including a roller frame engaging said supporting rail, a closed cylinder on said cross slide, a piston depending from said roller frame and extending into said cylinder, fluid under pressure in said cylinder holding said piston in spaced relation in said cylinder with respect to the upper end of said cylinder, turning devices for said grinding disks mounted on said support, means for adjusting said turning devices together in a direction parallel to said axis of said shaft, means for separately adjusting said turning devices perpendicular to said axis of said shaft, and electric means responsive to the position of at least one of said turning devices connected to said motor for controlling the speed of said grinding disks.

4. A grinding machine comprising a crossarm including a supporting nail, a cross slide, means suspending said cross slide from said supporting rail for horizontal movement therealong, a vertical slide mounted on said cross slide for vertical movement relative thereto, a support pivotally mounted on said vertical slide, a motor carried by said support, a shaft journalled in said support and driven by said motor, said shaft having an aXis of rotation spaced from the axis of rotation of said motor, grinding disks on said shaft, and a yoke propping said support secured to said vertical slide, said support being pivoted to said yoke, said means suspending said cross slide from said supporting rail including a roller frame engaging said supporting rail, a closed cylinder on said cross slide, a piston depending from said roller frame and extending into said cylinder, and fluid under pressure in said cylinder holding said piston in spaced relation in said cylinder with respect to the upper end of said cylinder.

5. A grinding machine comprising a cross arm including a supporting rail, a cross slide, means suspending said cross slide from said supporting rail for horizontal movement therealong, a vertical slide mounted on said cross slide for vertical movement relative thereto, hydraulic means for locking said vertical slide relative to said cross slide, a support pivotally mounted on said vertical slide, a motor carried by said support, a shaft journalled in said support and driven by said motor, said shaft having an axis of rotation spaced from the axis of rotation of said motor, grinding disks on said shaft, and a yoke propping said support secured to said vertical slide, said support being pivoted to said yoke.

6. A grinding machine comprising a cross arm including a horizontal supporting rail, a cross slide, means suspending said cross slide from said supporting rail for horizontal movement therealong, a vertical slide mounted on said cross slide for vertical movement relative thereto, a support pivotally mounted on said vertical slide and having a horizontal axis of rotation, a motor carried by said support, a shaft journalled in said support and driven by said motor, said shaft having an axis of rotation parallel to and spaced from the axis of rotation of said motor, a grinding disk at each end of said shaft, and a rigid yoke propping said support secured to said vertical slide, said support overbridging said motor and including a horizontal axle journalled in said yoke and having an axis normal to and between the axis of rotation of said motor and the axis of rotation of said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,112,716 Moor Oct. 6, 1914 1,338,355 Buskard Apr. 27, 1920 1,420,323 La Rock June 20, 1922 1,650,422 Brown Nov. 22, 1927 1,715,835 Honhorst et al June 4, 1929 1,778,132 Wegner Oct. 14, 1930 2,277,417 Scrivener Mar. 24, 1942 2,308,842 Wilson Jan. 19, 1943 2,629,210 Robinson Feb. 14, 1953 

